A wide variety of transistor types are known including bipolar transistors, field-effect transistors static induction transistors, and the like. Among such transistor types, field-effect transistors generally have a structure with a gate electrode formed via an insulating layer on a layer composed of a semiconductor material (active layer) on which a source electrode and drain electrode are connected. Among field-effect transistor types, in turn, organic transistors employing organic semiconductor compounds in the active layers exhibit advantages of light weight and flexibility and have numerous potential applications in electronic devices. The active layers of such organic transistors are usually formed by vapor deposition of organic semiconductor compounds, or spin coating, drop casting or printing of organic semiconductor compound-containing solutions, onto insulating layers that have been formed on substrates (Non-patent document 1).
In such organic transistors, the active layers are imparted with a prescribed orientation to enhance the carrier mobility. The advantage in terms of carrier mobility is attributed to the fact that the organic semiconductor compound of the active layer is aligned in a constant direction. As production processes for organic transistors that allow such orientation of active layers, there have been disclosed processes that include a step of providing a rubbing oriented film between the substrate and active layer (Non-patent documents 2 and 3), a step of rubbing the active layer (Non-patent document 4), or a step of forming an active layer composed of a friction-transfer film (Patent document 1). The organic transistors obtained by these production processes are known to have superior carrier mobility compared to those with non-oriented active layers.
[Non-patent document 1] “Technologies For Enhancing Operation of Organic Transistors”, 2003, Technical Information Institute Co., Ltd.
[Non-patent document 2] H. Sirringhaus et al., Appl. Phys. Lett., Vol. 77, No. 3, p. 406-408, 2002
[Non-patent document 3] M. L. Swiggers et al., Appl. Phys. Lett., Vol. 79, No. 9, p. 1300-1302, 2001
[Non-patent document 4] H. Heil et al., Appl. Phys. Lett., Vol. 93, No. 3, p. 1636-1641, 2003
[Patent document 1] Japanese Unexamined Patent Publication No. 2004-356422